The Design And Implementation Of Cross-platform Video Surveillance Transmission System On Chaos

Video surveillance technology is widely used to guarantee normal operation of equipment andsafety of property in modern society. As video signal transmission and preservation are involved invideo surveillance and for the sake of ensuring secrecy of video information without beingintercepted, the secure video signal transmission has become an important research direction. Thereare similarities between chaos and traditional cryptography, and chaotic encryption possesses thecharacteristics of high encryption rate as well as simple key management, so it is a challenging taskto explore theory and application of chaotic encryption. Based on the background, a securecross-platform chaotic video surveillance system was designed and implemented in local areanetwork in this paper. Combined with the actual hardware platform, an encryption algorithm relyingon chaotic encryption key generation and synchronization is designed. The designed system can runnormally on the hardware platform and achieve the desired effect. The research contents of thispaper include several parts as follows:(1) Tent map has the characteristic of uniform distribution but defects of narrow full map rangeand little parameters space. In order to obtain modified Tent map, an amplitude-modified Tent mapand a parameter-modified Tent map was designed respectively. By analyzing dynamiccharacteristics of the two modified map and the original Tent map, it is obvious to find that theamplitude-modified map can overcome the defect of fixed range while the parameter-modified mapovercome the defect of little parameters space. Both of the two modified map retain thecharacteristic of uniform distribution as the original Tent map has.(2) Research on process of digital quantization to discrete chaotic map. As the rate of digitalsequence generation has something to do with the rate of encryption algorithm, so we select arelatively faster digital quantitative method. Compared with threshold quantization method throughthe experimental proof, binary quantization method is faster, so we choose the binary quantizationmethod. Using this method, the digital sequence was obtained from three different mapsrespectively. By using test suite that NIST (National Institute of Standards and Technology) supplies,randomness test of the quantized discrete sequence was done, and test results indicate that thesequence extracted from two modified map has better pseudorandom properties. That is to say, suchsequence is more applicable for secure information system.(3) Design a key generation algorithm with variable parameters in order to encrypt videoinformation based on one-time pad technology. The chaotic encryption algorithm is based on twomodified Tent map. The algorithm is a kind of secret key-changed algorithm, so its security is better. As the secret key in the one frame one secret mode is controlled by a discrete map, the keymanagement is more simple and convenient. In order to verify the encryption rate, relevantexperiment is carried out. Test results prove that the encryption algorithm proposed has a faster rateover traditional encryption method and it is suitable for encryption occasions when meet mass data.(4) By learning chaotic encryption, embedded technology, network transmission and Qtcross-platform GUI framework, a cross-platform secure chaotic video surveillance system wasdesigned and implemented. In the course of experimenting on the system, hardware platform usedin capture terminal is ARM platform while display terminal is PC or ARM platform. Theexperiment indicated that the system can run normally on the hardware platform and achieved thedesired effect.